Atrial fibrillation is the most common heart arrhythmia, affecting more than 6 million Americans — a number projected to reach 12 million by 2030. If you or someone you love has been diagnosed with AFib, your cardiologist has almost certainly ordered an echocardiogram or will. Here's what the echo tells them, and why it's central to managing your care safely.
By Emanuel Papadakis, RDCS, RVT
Medically reviewed by Dr. Glenn Gandelman, MD, MPH, FACC, FASE — Board-Certified Cardiologist
January 2025
✓ARDMS Certified Sonographer
✓ASE Member — Echo Standards
✓IAC Accredited Cardiologist
✓Board-Certified Cardiologist Review
Atrial fibrillation is the most common sustained cardiac arrhythmia, affecting more than six million Americans. When AFib is diagnosed, one of the first things your physician should order is an echocardiogram. Here is why it is essential, and what it is specifically looking for.
Why AFib and Echocardiography Go Together
AFib causes the two upper chambers of the heart to quiver chaotically rather than contract in an organized rhythm. This has two major consequences that an echocardiogram directly addresses: blood stagnation and structural change. When the atria do not contract efficiently, blood pools in a small pouch called the left atrial appendage. Pooled blood clots. Clots in the left atrial appendage can break free and travel to the brain, causing stroke.
This is why stroke risk is five times higher in people with AFib than in those without it. The echocardiogram helps assess clot risk, evaluate structural damage, and guide treatment decisions including whether anticoagulation is appropriate and how aggressively to pursue rhythm control.
What the Echo Looks For in AFib Patients
›Left atrial size: An enlarged left atrium is both a cause and a consequence of AFib. A diameter above 4.0 cm significantly increases the likelihood of AFib persisting after cardioversion
›Left ventricular function: Rapid uncontrolled AFib can weaken the heart muscle over time, a condition called tachycardia-induced cardiomyopathy. The echo measures ejection fraction to detect this
›Valvular disease: Mitral valve stenosis is a known AFib trigger. The echo evaluates all valves to identify structural causes of the arrhythmia
›Diastolic dysfunction: Stiffening of the left ventricle increases atrial pressure and promotes AFib. The echo grades this from mild to severe
›Pericardial effusion: Fluid around the heart, which can occur with certain medications or inflammatory conditions associated with AFib
Before Cardioversion: Why Timing Matters
If a physician plans to restore normal rhythm through electrical cardioversion or medication, they need to know whether a clot has formed in the left atrial appendage. Cardioverting the heart while a clot is present can dislodge it and cause a stroke. The standard protocol requires either three or more weeks of therapeutic anticoagulation or a transesophageal echo confirming no thrombus before cardioversion proceeds.
The standard transthoracic echo BlackPoint performs does not directly visualize the left atrial appendage with sufficient clarity to rule out thrombus. However, it provides the structural information that guides anticoagulation strategy and overall AFib management, and is the appropriate and standard first step.
Guiding Long-Term AFib Management
Beyond initial evaluation, echocardiograms are used to monitor the heart response to AFib treatment over time. If rate control medications are used, serial echos track whether ventricular function is being preserved. If rhythm has been successfully controlled, left atrial size can actually decrease, a sign of favorable cardiac remodeling.
For patients considering ablation procedures, pre-procedural echocardiography provides the anatomical baseline cardiologists use to plan the approach and assess candidacy. It is a foundational test at every stage of AFib management.
If you have been diagnosed with AFib and have not had a formal echocardiogram, or if it has been several years since your last one, BlackPoint can perform this test at your home in 30 to 45 minutes. Written cardiologist report in 24 to 48 hours. $397, no referral required.
Frequently Asked Questions
Can an echocardiogram detect atrial fibrillation?
An echocardiogram does not diagnose AFib directly — an EKG or heart monitor does that by recording electrical rhythm. What an echo reveals is the structural damage AFib causes: enlarged atria, reduced ejection fraction, valve dysfunction, and conditions that increase clot risk. It is the standard next step after an AFib diagnosis.
Can you see AFib on an echo?
You cannot see the irregular electrical rhythm itself, but you can see its consequences. Left atrial enlargement, reduced left ventricular function, mitral valve regurgitation, and spontaneous echo contrast (a swirling pattern in blood suggesting slow flow and clot risk) are all visible findings associated with AFib.
Do I need an echocardiogram if I have been diagnosed with AFib?
Yes. The American College of Cardiology and American Heart Association recommend a transthoracic echocardiogram for all patients with a new AFib diagnosis. It establishes baseline heart function, identifies structural causes, and guides treatment decisions including anticoagulation strategy.
What is the difference between an EKG and echocardiogram for AFib?
An EKG records electrical activity and confirms the irregular rhythm. An echocardiogram uses ultrasound to image heart structure and function — chamber sizes, valve movement, wall motion, ejection fraction. The EKG tells you the rhythm is abnormal; the echo tells you what that rhythm is doing to the heart. Both are needed for complete AFib evaluation.
How often should I get an echocardiogram with AFib?
After the initial baseline echo, follow-up frequency depends on findings and treatment. Patients with reduced ejection fraction or significant valve disease typically repeat the study every 6 to 12 months. Patients with normal initial findings and well-controlled AFib may repeat every 1 to 3 years or when symptoms change.
